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pnmtoddif - Convert a portable anymap to DDIF format
pnmtoddif
pnmtoddif [-resolution x y] [pnmfile [ddiffile]]
- resolution x y
- The
horizontal and vertical resolution of the output image in dots per inch.
Defaults to 78 dpi.
- pnmfile
- The filename for the image file in pnm format.
If this argument is omitted, input is read from stdin.
- ddiffile
- The filename
for the image file to be created in DDIF format. If this argument is omitted,
the ddiffile is written to standard output. It can only specified if a pnmfile
is also specified.
CWpnmtoddif takes a portable anymap from
standard input and converts it into a DDIF image file on standard output
or the specified DDIF file.
pbm format (bitmap) data is written as 1 bit
DDIF, pgm format data (greyscale) as 8 bit greyscale DDIF, and ppm format
data is written as 8,8,8 bit color DDIF. All DDIF image files are written
as uncompressed. The data plane organization is interleaved by pixel.
In
addition to the number of pixels in the width and height dimension, DDIF
images also carry information about the size that the image should have,
that is, the physical space that a pixel occupies. PBMPLUS images do not
carry this information, hence it has to be externally supplied. The default
of 78 dpi has the beneficial property of not causing a resize on most
Digital Equipment Corporation color monitors.
Burkhard Neidecker-Lutz
Digital Equipment Corporation, CEC Karlsruhe
neideck@nestvx.enet.dec.com
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